Why are wear rings installed in a pump?

Wear rings are installed in pumps primarily to concentrate wear on these specific components instead of allowing wear to occur on the more expensive and critical components, such as the volute and impeller. By designing the pump with wear rings, any abrasion or wear that occurs during operation can be easily managed and replaced without significant disruption or cost. This protective measure extends the overall lifespan of the pump and maintains efficiency, as it helps ensure that the clearance between the impeller and volute remains optimal for proper fluid dynamics. In essence, wear rings serve as sacrificial elements, minimizing the impact of operational wear and tear on more central parts of the pump.

Other answers might suggest benefits such as increased efficiency, reduced noise, or lubrication, but these do not directly relate to the primary function of wear rings as protective replacements for more critical parts in the pump's structure.